X-Original-To: pgsql-general-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 784C03A4227 for ; Mon, 25 Oct 2004 22:08:51 +0100 (BST) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 81249-09 for ; Mon, 25 Oct 2004 21:08:48 +0000 (GMT) Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by svr1.postgresql.org (Postfix) with ESMTP id F421C3A41EC for ; Mon, 25 Oct 2004 22:08:49 +0100 (BST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id i9PL8nWF028075; Mon, 25 Oct 2004 17:08:49 -0400 (EDT) To: Glenn Sullivan Cc: pgsql-general Subject: Re: shared buffers In-reply-to: <417D629C.7000805@varianinc.com> References: <417D629C.7000805@varianinc.com> Comments: In-reply-to Glenn Sullivan message dated "Mon, 25 Oct 2004 14:31:24 -0600" Date: Mon, 25 Oct 2004 17:08:49 -0400 Message-ID: <28074.1098738529@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.0 tagged_above=0.0 required=5.0 tests= X-Spam-Level: X-Archive-Number: 200410/1194 X-Sequence-Number: 67717 Glenn Sullivan writes: > What is the performance issue with setting shared_buffers to something like 45? > In doing some timing on my system, I cannot tell any difference with 45 versus 1000. What are you timing exactly? Almost every benchmark I've ever seen is much happier with shared_buffers of at least a few hundred. Otherwise you spend too much time copying data between kernel and user space. regards, tom lane